1. Field of the Invention
The invention relates to a vehicle seat having a thigh support which can be adjusted both in the longitudinal direction of the seat and about an axis running in the lateral direction of the seat and can be locked in selectable positions relative to the rear section of the seat portion which carries a back rest. The upholstery of this thigh support lies on an upholstery support which is borne by at least one support which projects forward from the frame of the rear section of the seat portion.
2. Description of the Prior Art
A vehicle seat of this type is already known, for example, see West German Pat. No. 1,099,866. In the known seat, the support of the thigh support is formed so as to be capable of being extended in the longitudinal direction. The rear end of the support is pivotably mounted on the adjacent seat portion by means of an adjusting and locking hinge and supports a rear upholstery element. At its forward end, the support includes a second, forward upholstery element whose distance from the rear upholstery element increases when the support is extended in the longitudinal direction. An upholstery covering, which extends from the rear upholstery element to the forward upholstery element, must therefore be made so as to be extensible. In the known vehicle seat, this circumstance is dealt with in that the forward end of the covering is wrapped downwardly around the front upholstery element and is held tight by tension springs provided on the underside of the thigh supports. The disadvantage thereof is that, as the amount of extension increases, the resulting higher tension in the springs increasingly compresses the upholstery elements supporting the covering and the upholstery elements thereby become harder. The size of the usable adjustment range in the longitudinal direction is therefore insufficient. Because of the large distance between the front and rear upholstery elements of the thigh supports, in the known seat it often occurs that the covering between the two upholstery elements is pressed down, even when strong springs are used to hold the upholstery covering tight, i.e. the support of the upper thighs of the seat user is not accomplished over a large area, but essentially only in the area of the front upholstery element. The thigh supports therefore cannot contribute to the desired degree towards improving the comfort of the seat. The use of stronger springs to tighten the covering also presents the danger of tearing the covering. In addition, assembling the thigh supports is difficult and time-consuming.